Re: [PATCH] usertools: suggest use of hwloc for new cpu

[Ferruh Yigit <ferruh.yigit@amd.com>]

On 8/14/2023 10:25 AM, Konstantin Ananyev wrote:
> 
>> On Sun, Aug 13, 2023 at 08:52:01AM -0700, Stephen Hemminger wrote:
>>> On Sun, 13 Aug 2023 02:12:03 +0000
>>> "Varghese, Vipin" <Vipin.Varghese@amd.com> wrote:
>>>
>>>>>
>>>>> On Sat, 12 Aug 2023 06:27:20 +0530
>>>>> Vipin Varghese <vipin.varghese@amd.com> wrote:
>>>>>
>>>>>> Most modern processor now supports numa by partitioning NUMA based on
>>>>>> CPU-IO & Last Level Cache within the same socket.
>>>>>> As per the discussion in mailing list, suggesting the make use of
>>>>>> hw-loc for such scenarios.
>>>>>>
>>>>>> Signed-off-by: Vipin Varghese <vipin.varghese@amd.com>
>>>>>
>>>>> NAK, no scripting hwloc, it is ugly and creates a dependency that is not listed
>>>>> in DPDK packaging.
>>>>
>>>> There is no calls to hwloc within in thescript. Hence not clear what does ` NAK, no scripting hwloc it is ugly and creates a
>> dependency that is not listed in DPDK packaging.`.
>>>>
>>>> Requesting to cross check why NAK is shared for `print` as suggestion. Hence, I have disagree to this.
>>>
>>> Sorry, I misinterpreted what the print's were doing.
>>> Better off not to list exact flags, the lstopo may change and user may want different
>>> format anyway.
>>>
>>> How about something like this?
>>>
>>>
>>>  doc/guides/rel_notes/deprecation.rst | 5 +++++
>>>  usertools/cpu_layout.py              | 5 +++++
>>>  2 files changed, 10 insertions(+)
>>>
>>> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
>>> index 317875c5054b..25a116900dfb 100644
>>> --- a/doc/guides/rel_notes/deprecation.rst
>>> +++ b/doc/guides/rel_notes/deprecation.rst
>>> @@ -185,3 +185,8 @@ Deprecation Notices
>>>    will be deprecated and subsequently removed in DPDK 24.11 release.
>>>    Before this, the new port library API (functions rte_swx_port_*)
>>>    will gradually transition from experimental to stable status.
>>> +
>>> +* cpulayout: The CPU layout script is unable to deal with all the possible
>>> +  complexities of modern CPU topology. Other existing tools offer more
>>> +  features and do a better job with keeping up with innovations.
>>> +  Therefore it will be deprecated and removed in a future release.
>>
>> Does the script really do that bad a job? While I can understand us looking
>> to recommend alternatives, I actually find the script in it's current form
>> really handy - much more so than working out the exact flags for lstopo
>> etc. Since it's not a large maintenance burden, I'd request we keep it
>> around - while still recommending lstopo to users.
> 
> +1
> I do use it on regular basis.
> It would be a pity if it will be gone.
>

I also use it time to time and find it useful.

But it is not accurate/correct for some AMD platforms (for various NPS
(Nodes per Socket) values).
So either it needs to be updated/improved or replaced.

Vipin sent a patch [1] to update it but it is question how much of this
logic belongs to DPDK, or should we rely on external tools dedicated for
this purpose.


Both are OK, if we can give a decision we can proceed on that direction.


[1]
https://patchwork.dpdk.org/project/dpdk/patch/20220326073207.489694-1-vipin.varghese@amd.com/